通过 Native Query 组合多个参数进行搜索

Question

我目前正在开发一个功能，该功能将允许系统通过 6 个参数的组合来搜索公共服务收据，这些参数可以为空，这意味着收据不应被此参数过滤：accountNumber、amountRangeMin、amountRangeMax、dateRangeMin , dateRangeMax, publicServiceId。然而，为每个参数组合创建一个方法不是一种选择，我认为必须有更好的方法，起初我的方法如下：

在我的服务中，我有这个方法：

public Map<String,Object> findPublicServiceReceiptsByParams(Integer accountNumber, BigDecimal amountRangeMin,
        BigDecimal amountRangeMax, LocalDate dateRangeMin, LocalDate dateRangeMax, Integer publicServiceId) {
    Map<String,Object> publicServiceReceipts = new HashMap<String,Object>();
    String accountNumberFilter = !(accountNumber==null) ? accountNumber.toString() : "AccountNumberTableName";
    String amountRangeMinFilter = !(amountRangeMin==null) ? amountRangeMin.toString() : "table.AmountColumnName";
    String amountRangeMaxFilter = !(amountRangeMax==null) ? amountRangeMax.toString() : "table.AmountColumnName";
    String dateRangeMinFilter = !(dateRangeMin==null) ? dateRangeMin.toString() : "Table.ReceiptCreationDateColumn";
    String dateRangeMaxFilter = !(dateRangeMax==null) ? dateRangeMax.toString() : "Table.ReceiptCreationDateColumn";
    String publicServiceIdFilter = !(publicServiceId==null) ? publicServiceId.toString() : "table.publicServiceIdColumn";
    publicServiceReceipts = publicServiceReceiptRepository.findPublicServiceReceiptsByParams(accountNumberFilter,
            amountRangeMinFilter, amountRangeMaxFilter, dateRangeMinFilter, dateRangeMaxFilter,
            publicServiceIdFilter);
    return publicServiceReceipts;
}

然后在我的存储库中我有：

final static String FIND_PUBLIC_SERVICES_BY_ARGS = "Select (Insert whatever logic should go in here to select columns from receipts the where clause is the one that matters)"
        + "    WHERE ACT.ACT_AccountNumber=:accountNumberFilter\n"
        + "      AND PSE.PSE_Id=:publicServiceIdFilter\n"
        + "      AND PSR.PSR_CreateDate BETWEEN :dateRangeMinFilter AND :dateRangeMaxFilter\n"
        + "      AND PSR.PSR_Amount BETWEEN :amountRangeMinFilter AND :amountRangeMaxFilter\n"
        + " order by PSR.PSR_CreateDate desc";

@Query(nativeQuery = true, value = FIND_PUBLIC_SERVICES_BY_ARGS)
Map<String, Object> findPublicServiceReceiptsByParams(@Param("accountNumberFilter") String accountNumberFilter,
        @Param("amountRangeMinFilter") String amountRangeMinFilter,
        @Param("amountRangeMaxFilter") String amountRangeMaxFilter,
        @Param("dateRangeMinFilter") String dateRangeMinFilter,
        @Param("dateRangeMaxFilter") String dateRangeMaxFilter,
        @Param("publicServiceIdFilter") String publicServiceIdFilter);

}

我的理由是，如果参数为 null 意味着使用 Web 服务的人对该参数不感兴趣，所以如果发生这种情况，我将该变量设置为列名称，这样它就不会影响 WHERE 子句和理论使它更简单，但我发现它会将名称作为字符串发送，因此它不会被识别为 sql 语句，这是我思维中的缺陷，正如我所说，除了编写每种方法之外，必须有另一种方法对于每种组合，我都感谢您的帮助:)。

Answer 1

我找到了解决这个问题的方法，我是这样做的（我将只显示本机查询，因为它是我唯一改变的东西）：

DECLARE  @actNum varchar(50),@crdNum varchar(50),@pseId varchar(50),@dateMin varchar(50),@dateMax varchar(50),@amountMin varchar(50),@amountMax varchar(50)
SET @actNum = :actNum
SET @crdNum = :crdNum 
SET @pseId =  :pseId 
SET @dateMin = :dateMin 
SET @dateMax = :dateMax 
SET @amountMin = :amountMin 
SET @amountMax = :amountMax 
--Whatever Select with joins statement
                   WHERE ACT.ACT_AccountNumber = CASE WHEN @actNum = 'N/A' 
                                             THEN ACT.ACT_AccountNumber 
                                             ELSE @actNum END
                 AND CRD_CardNumber = CASE WHEN @crdNum = 'N/A' 
                                      THEN CRD_CardNumber 
                                      ELSE @crdNum END
                 AND PSE.PSE_Id= CASE WHEN @pseId = 'N/A' 
                                 THEN PSE.PSE_Id 
                                 ELSE @pseId END
                 AND PSR.PSR_CreateDate >= CASE WHEN @dateMin = 'N/A' 
                                                THEN PSR.PSR_CreateDate 
                                                ELSE @dateMin END 
                                        AND PSR.PSR_CreateDate <= CASE WHEN @dateMax = 'N/A' 
                                            THEN PSR.PSR_CreateDate 
                                            ELSE @dateMax END
                 AND PSR.PSR_Amount BETWEEN CASE WHEN @amountMin = 'N/A' 
                                            THEN PSR.PSR_Amount 
                                            ELSE @amountMin END 
                                    AND CASE WHEN @amountMax = 'N/A' 
                                        THEN PSR.PSR_Amount 
                                        ELSE @amountMax END 
            ORDER BY PSR.PSR_CreateDate DESC

后端会将参数作为“N/A”（如果不应该用于过滤数据）或实际值发送，这对我来说很好！

Answer 2

您应该使用Criteria API，它专为创建动态查询而设计。在这种情况下，命名查询并不是真的要使用。 有了它，您可以执行以下操作：

@PersistenceContext
EntityManager em;

List<YourEntity> method(String argument) {
    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<YourEntity> cq = cb.createQuery(YourEntity.class);
    Root<YourEntity> root = cq.from(YourEntity.class);

    List<Predicate> predicates = new ArrayList<>();
    if (argument == null) {
        predicates.add(cb.equal(root.get("yourAttribute"), argument);
    }
    // rest of your logic goes here

    cq.where(predicates.toArray(new Predicate[]{}));
    return em.createQuery(cq).getResultList();
}